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K.-d. Kniffki - One of the best experts on this subject based on the ideXlab platform.
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Responses of neurons in the lateral thalamus of the cat to stimulation of urinary bladder, colon, esophagus, and skin.
Brain research, 1999Co-Authors: A.c. Horn, M Petersen, C Vahle-hinz, J Brüggemann, K.-d. KniffkiAbstract:In seven female alpha-chloralose-anesthetized cats, 52 lateral thalamic neurons were tested with noxious distension of the urinary bladder, the distal colon and the lower esophagus. In addition, the neurons were characterized with innocuous and noxious mechanical stimulation of the skin and deep structures. Of the 52 neurons tested, 32 (62%) were visceroceptive. Of these visceroceptive neurons, 20 (63%) were located in the periphery of the Ventral Posterolateral Nucleus (VPLp), 10 (31%) in the adjacent posterior complex (PO), and two (6%) in the ventrolateral Nucleus (VL). No differences were found with respect to location between neurons responsive or unresponsive to visceral stimulation. Ten neurons (31%) received input from more than one viscus and, therefore, showed viscerovisceral convergence. Excitatory or "inhibitory" responses were elicited by stimulation of the esophagus in 21 neurons, of the colon in 13, and of the urinary bladder in 11 neurons. No indications were found for a segregation of neurons responsive to a certain viscus and their location in VPLp or PO. Of 51 neurons, for which a somatic receptive field was determined, 44 (86%) exhibited low threshold type (LT), and seven (14%) wide dynamic range type (WDR) responses. The data indicate that there might exist a somatovisceral coregistration, because many neurons (69%) had homosegmental receptive fields, and bladder stimulation was the most successful stimulus. It is concluded that VPLp and the adjacent PO in the cat play a role in the perception and localization of painful events originating from thoracic and pelvic organs.
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Projections from the renal nerve to the cat's lateral somatosensory thalamus
Brain research, 1997Co-Authors: A.c. Horn, Johannes Brüggemann, Christiane Vahle-hinz, M Petersen, K.-d. KniffkiAbstract:Abstract The representation of the kidney in the lateral somatosensory thalamus was mapped using electrical stimulation of the renal nerve in pentobarbitone-anesthetized cats. Ninety-five of 197 thalamic neurons studied responded to renal nerve stimulation. The responsive neurons were located in the periphery of the Ventral Posterolateral Nucleus (42%, VPLp) and the neighboring dorsal and lateral aspects of the posterior complex (58%; POd and POl). No visceroceptive neurons were found within VPL proper. The mean response latency of the thalamic neurons to electrical nerve stimulation was 9.5 ± 2.6 ms (mean ± S.D.), suggesting an involvement of A δ, and possibly A β fibers in the primary afferent pathway. The visceroceptive neurons were further characterized with innocuous mechanical stimulation of the body surface, and for 94 of the 95 neurons a somatic receptive field could be determined. Of these, 35% were located on the lower back and belly, i.e., the dermatomes of the lower thoracic and upper lumbar spinal projection areas of the renal nerve. 52% of the somatic receptive fields were located on the contralateral foot, thigh, tail, or hind leg (lower lumbar, sacral and coccygeal dermatomes) and 13% covered the arm and upper body (upper thoracic and lower cervical dermatomes). Comparison between the thalamic representations of the renal and pelvic nerves showed that both covered comparable areas adjacent and around, but not within VPL proper. It is concluded that VPLp, POd and POl play a role in processing visceral, possibly including nociceptive, information from the kidney of the cat.
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Projections from the pelvic nerve to the periphery of the cat's thalamic Ventral Posterolateral Nucleus and adjacent regions of the posterior complex.
Journal of neurophysiology, 1994Co-Authors: Johannes Brüggemann, Christiane Vahle-hinz, K.-d. KniffkiAbstract:1. Mapping experiments were performed in the region of the Ventral Posterolateral Nucleus of the lateral thalamus in pentobarbitone-anesthetized cats with the aim to locate foci with input from the...
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Representation of the urinary bladder in the lateral thalamus of the cat
Journal of neurophysiology, 1993Co-Authors: Johannes Brüggemann, Christiane Vahle-hinz, K.-d. KniffkiAbstract:1. In alpha-chloralose-anesthetized cats the region surrounding the Ventral Posterolateral Nucleus (VPL) of the thalamus was investigated to locate foci with input from the urinary bladder stimulat...
W D Willis - One of the best experts on this subject based on the ideXlab platform.
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Visceral nociceptive input into the Ventral Posterolateral Nucleus of the thalamus: a new function for the dorsal column pathway
Journal of neurophysiology, 1996Co-Authors: E D Al-chaer, N B Lawand, Karin N. Westlund, W D WillisAbstract:1. Extracellular recordings were made from single neurons in the Ventral Posterolateral (VPL) Nucleus of the thalamus in anesthetized male rats. VPL cells that responded to colorectal distension (C...
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Is there a pathway in the posterior funiculus that signals visceral pain?
Pain, 1996Co-Authors: R M Hirshberg, E D Al-chaer, N B Lawand, K N Westlund, W D WillisAbstract:The present report provides evidence that axons in the medial part of the posterior column at T10 convey ascending nociceptive signals from pelvic visceral organs. This evidence was obtained from human surgical case studies and histological verification of the lesion in one of these cases, along with neuroanatomical and neurophysiological findings in animal experiments. A restricted lesion in this area can virtually eliminate pelvic pain due to cancer. The results remain excellent even in cases in which somatic structures of the pelvic body wall are involved. Following this procedure, neurological testing reveals no additional neurological deficit. There is no analgesia to pinprick stimuli applied to the body surface, despite the relief of the visceral pain. Since it is reasonable to attribute the favorable results of limited midline myelotomies to the interruption of axons of visceral nociceptive projection neurons in the posterior column, we have performed experiments in rats to test this hypothesis. The results in rats indicate that the dorsal column does indeed include a nociceptive component that signals pelvic visceral pain. The pathway includes neurons of the postsynaptic dorsal column pathway at the L6-S1 segmental level, axons of these neurons in the fasciculus gracilis, and neurons of the Nucleus gracilis and the Ventral Posterolateral Nucleus of the thalamus.
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Glutamate-immunoreactive terminals synapse on primate spinothalamic tract cells.
The Journal of comparative neurology, 1992Co-Authors: K N Westlund, D. Zhang, S M Carlton, W D WillisAbstract:Glutamate has been shown to excite spinothalamic tract (STT) neurons and has been localized to primary afferent neurons, spinal cord projection neurons, and interneurons in the spinal cord dorsal horn. The likelihood that glutamate-immunoreactive (GLU-IR) terminals directly innervate STT neurons was investigated. For these studies three lamina IV or V STT cells in the lumbar spinal cords of three monkeys (Macaca fascicularis) were identified electrophysiologically and characterized. Two were identified as high threshold neurons and one as a wide dynamic range neuron. Following intracellular injection of the cells with HRP and reaction to give the cells a Golgi-like appearance, the tissues were processed for electron microscopy. Postembedding immunogold methods with antibodies specific for glutamate were used to identify GLU-IR terminals apposing the somata and dendrites of the STT neurons, including dendrites that extended into laminae IV and III. The GLU-IR terminals were numerous and constituted a mean of 46% of the population counted that appose the STT soma and 50% of the profiles apposing the dendrites. Fifty-four percent of the somatic and 50% of the dendritic surface length was contacted by GLU-IR terminals. Most terminals contained round clear vesicles and some contained a variable number of large dense core vesicles. For one of the three cells examined it was determined that 45% of the terminals apposing the soma were GLU-IR and 30% of the terminals were gamma aminobutyric acid-immunoreactive (GABA-IR). In an additional monkey, a lamina I cell retrogradely labeled from the Ventral Posterolateral Nucleus of the thalamus was found to be ensheathed in glial processes.(ABSTRACT TRUNCATED AT 250 WORDS)
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Noradrenergic innervation of somatosensory thalamus and spinal cord.
Progress in brain research, 1991Co-Authors: Karin N. Westlund, L.s. Sorkin, Susan M. Carlton, D. Zhang, W D WillisAbstract:Monoamine systems have been shown to be an important part of an endogenous analgesic system of the central nervous system. Some aspects of the anatomical basis of monoamine modulation of nociceptive input were investigated in these studies. Two sites examined where monoamine systems are known to impinge on the pain transmission system included the grey matter of the somatosensory thalamus and the spinal cord. In particular, the connections of noradrenergic systems with these regions were emphasized. In the Ventral Posterolateral Nucleus of the thalamus the presence of a sparse innervation by both noradrenergic and serotonergic fibers was confirmed by electron microscopy. Boutons containing markers for either serotonin or norepinephrine were observed contacting dendrites and somata in this region. The origins of these projections were determined, by retrograde transport studies, to be primarily in the locus coeruleus and the dorsal raphe. Also examined was noradrenergic innervation of the spinothalamic tract neurons which relay information related to pain from the spinal cord. Some catecholamine boutons were observed to contact spinothalamic neurons directly. These included spinothalamic tract neurons of the wide dynamic range and the high threshold category. The presence of noradrenergic elements in the somatosensory thalamus and, in particular, the direct connection with spinothalamic tract neurons at the level of the spinal cord clearly provides an anatomical substrate for influencing sensory mechanisms related to pain.
Johannes Brüggemann - One of the best experts on this subject based on the ideXlab platform.
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Viscerosomatic interactions in the thalamic Ventral Posterolateral Nucleus (VPL) of the squirrel monkey.
Brain research, 1998Co-Authors: Johannes Brüggemann, Ting Shi, A. Vania ApkarianAbstract:Abstract In anesthetized squirrel monkeys single cell recordings were performed using tungsten microelectrodes. The responses of 29 viscerosomatoceptive and somatoceptive VPL neurons to noxious distension of the urinary bladder, the lower esophagus and the distal colon and to innocuous and noxious somatic stimuli were assessed when these stimuli were presented separately or together. Neuronal responses were defined as additive or interactive depending on the relative changes in responses to individual somatic or visceral stimuli, and on their responses during conditioning (somatic and visceral stimuli applied concurrently). In 13 neurons interactions between the somatosensory and visceral inputs could be demonstrated. The dominant interactive effect was inhibition, although facilitatory effects were seen as well (2 of 13). The magnitude or direction of the interactions seemed independent of the location of the somatic and visceral receptive fields. The mean population response of the neurons showing interactions was 4.66 spikes/s to somatic stimulation, and 0.07 spikes/s to visceral stimulation. During conditioning the mean interactive effect was −62% of the calculated additive effect. This implies that overall the somatic responses are halved during a coincident visceral stimulus. In a subgroup of the VPL neurons, which were classified as pure somatic responsive (n=14) due to their unresponsiveness during visceral stimulation alone, a third (n=5) still exhibited visceral convergence during conditioning. The latter neurons, therefore, receive visceral inputs, which function in a purely interactive (modulatory) manner. It is concluded that part of the described effects is due to competition (cross modality suppression) between the visceral and somatic inputs. We further conclude that the suppression of somatic information by noxious visceral stimuli may contribute to a more effective processing of the discriminatory aspects of nociceptive visceral information previously demonstrated in VPL.
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Projections from the renal nerve to the cat's lateral somatosensory thalamus
Brain research, 1997Co-Authors: A.c. Horn, Johannes Brüggemann, Christiane Vahle-hinz, M Petersen, K.-d. KniffkiAbstract:Abstract The representation of the kidney in the lateral somatosensory thalamus was mapped using electrical stimulation of the renal nerve in pentobarbitone-anesthetized cats. Ninety-five of 197 thalamic neurons studied responded to renal nerve stimulation. The responsive neurons were located in the periphery of the Ventral Posterolateral Nucleus (42%, VPLp) and the neighboring dorsal and lateral aspects of the posterior complex (58%; POd and POl). No visceroceptive neurons were found within VPL proper. The mean response latency of the thalamic neurons to electrical nerve stimulation was 9.5 ± 2.6 ms (mean ± S.D.), suggesting an involvement of A δ, and possibly A β fibers in the primary afferent pathway. The visceroceptive neurons were further characterized with innocuous mechanical stimulation of the body surface, and for 94 of the 95 neurons a somatic receptive field could be determined. Of these, 35% were located on the lower back and belly, i.e., the dermatomes of the lower thoracic and upper lumbar spinal projection areas of the renal nerve. 52% of the somatic receptive fields were located on the contralateral foot, thigh, tail, or hind leg (lower lumbar, sacral and coccygeal dermatomes) and 13% covered the arm and upper body (upper thoracic and lower cervical dermatomes). Comparison between the thalamic representations of the renal and pelvic nerves showed that both covered comparable areas adjacent and around, but not within VPL proper. It is concluded that VPLp, POd and POl play a role in processing visceral, possibly including nociceptive, information from the kidney of the cat.
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Projections from the pelvic nerve to the periphery of the cat's thalamic Ventral Posterolateral Nucleus and adjacent regions of the posterior complex.
Journal of neurophysiology, 1994Co-Authors: Johannes Brüggemann, Christiane Vahle-hinz, K.-d. KniffkiAbstract:1. Mapping experiments were performed in the region of the Ventral Posterolateral Nucleus of the lateral thalamus in pentobarbitone-anesthetized cats with the aim to locate foci with input from the...
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Representation of the urinary bladder in the lateral thalamus of the cat
Journal of neurophysiology, 1993Co-Authors: Johannes Brüggemann, Christiane Vahle-hinz, K.-d. KniffkiAbstract:1. In alpha-chloralose-anesthetized cats the region surrounding the Ventral Posterolateral Nucleus (VPL) of the thalamus was investigated to locate foci with input from the urinary bladder stimulat...
John P Williams - One of the best experts on this subject based on the ideXlab platform.
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A New Rat Model of Thalamic Pain Produced by Administration of Cobra Venom to the Unilateral Ventral Posterolateral Nucleus.
Pain physician, 2019Co-Authors: Wan-rui Shi, Jian-feng Zhang, Xiao-yan Qian, Qi-wu Fang, Yong Wang, John P WilliamsAbstract:Background Thalamic pain is a neuropathic pain syndrome that occurs as a result of thalamic damage. It is difficult to develop therapeutic interventions for thalamic pain because its mechanism is unclear. To better understand the pathophysiological basis of thalamic pain, we developed and characterized a new rat model of thalamic pain using a technique of microinjecting cobra venom into the Ventral Posterolateral Nucleus (VPL) of the thalamus. Objectives This study will establish a new thalamic pain rat model produced by administration of cobra venom to the unilateral Ventral Posterolateral Nucleus. Study design This study used an experimental design in rats. Setting The research took place in the laboratory at the Aviation General Hospital of China Medical University and Beijing Institute of Translational Medicine. Methods Male Sprague-Dawley rats were subjected to the administration of cobra venom or saline into the left VPL. The development of mechanical hyperalgesia and changes in pain-related behaviors and motor function were measured after intrathalamic cobra venom microinjection using the von Frey test, video recording, and cylinder test, respectively. On postoperative days 7 to 35, both electroacupuncture and pregabalin (PGB) were administered to verify that the model reproduced the findings in humans. Moreover, the organizational and structural alterations of the thalamus were examined via transmission electron microscopy (TEM). Results The threshold for mechanical stimuli in the left facial skin was significantly decreased on day 3 after thalamic pain modeling as compared with pre-venom treatment. Furthermore, the ultrastructural alterations of neurons such as indented neuronal nuclei, damaged mitochondria and endoplasmic reticulum, and dissolved surrounding tissues were observed under TEM. Moreover, electroacupuncture treatment ameliorated mechanical hyperalgesia, pain-like behaviors, and motor dysfunction, as well as restore normal structures of neurons in the thalamic pain rat model. However, no such beneficial effects were noted when PGB was administered. Limitations The pathophysiological features were different from the present model and the patients in clinical practice (in most cases strokes, either ischemic or hemorrhagic). Conclusion The cobra venom model may provide a reasonable model for investigating the mechanism of thalamic pain and for testing therapies targeting recovery and pain after thalamic lesions. Key words Thalamic pain, cobra venom, electroacupuncture, pregabalin, indented neuronal nuclei, damaged mitochondria, dissolved endoplasmic reticulum, golgi body.
A. Vania Apkarian - One of the best experts on this subject based on the ideXlab platform.
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Viscerosomatic interactions in the thalamic Ventral Posterolateral Nucleus (VPL) of the squirrel monkey.
Brain research, 1998Co-Authors: Johannes Brüggemann, Ting Shi, A. Vania ApkarianAbstract:Abstract In anesthetized squirrel monkeys single cell recordings were performed using tungsten microelectrodes. The responses of 29 viscerosomatoceptive and somatoceptive VPL neurons to noxious distension of the urinary bladder, the lower esophagus and the distal colon and to innocuous and noxious somatic stimuli were assessed when these stimuli were presented separately or together. Neuronal responses were defined as additive or interactive depending on the relative changes in responses to individual somatic or visceral stimuli, and on their responses during conditioning (somatic and visceral stimuli applied concurrently). In 13 neurons interactions between the somatosensory and visceral inputs could be demonstrated. The dominant interactive effect was inhibition, although facilitatory effects were seen as well (2 of 13). The magnitude or direction of the interactions seemed independent of the location of the somatic and visceral receptive fields. The mean population response of the neurons showing interactions was 4.66 spikes/s to somatic stimulation, and 0.07 spikes/s to visceral stimulation. During conditioning the mean interactive effect was −62% of the calculated additive effect. This implies that overall the somatic responses are halved during a coincident visceral stimulus. In a subgroup of the VPL neurons, which were classified as pure somatic responsive (n=14) due to their unresponsiveness during visceral stimulation alone, a third (n=5) still exhibited visceral convergence during conditioning. The latter neurons, therefore, receive visceral inputs, which function in a purely interactive (modulatory) manner. It is concluded that part of the described effects is due to competition (cross modality suppression) between the visceral and somatic inputs. We further conclude that the suppression of somatic information by noxious visceral stimuli may contribute to a more effective processing of the discriminatory aspects of nociceptive visceral information previously demonstrated in VPL.
